Slack adjuster



Feb. 20, 1923.

2 'SHEETS-SERT HLED DEC.28,192I.

if l L www INVENTQR CLA/DE G.- FARMER INVENToR C I YDE C. FARMER ATTORNEY Patented Feb. 20, 1923.

risalta l oLYnE c. FARMER, or PITTSBURGH, PnNNsYLvA-Nraessreivon -rofTiIEfWnsINGsf HOUSE AIP. BRAKE COMPANY, or WILMERDING, .rENNsYLvANrAVA CORPORATION. 'i

. or PENNSYLVANIA.' i

sLAcK Amos-rait. I, 1

Ap'pnoationnioa December as, 192i. serial No. 525,400. y' f Tol al?. whom t may concern.: j

Be itrknown that I', CLYDEC.- FARMER, aV citizen of the United States, residing at Pittsburgh, in the county' of Allegheny and State ol Pennsylvania, lhave invented new and. useful Improvements in Slack Ad:- justers, of which the following is` a speci;

iicationffl r v ,1

This invention relates'to slack adjusters for-'automatically taking up slack due tothe wear of the brake shoes onl thecar wheels. Vith certain rotherwise desirable types of brake slack adj usters, it has been found thatj the movable members vof thejslack adjuster are liable to be operated when 'not intended by themomentum of the parts, due tothe application of a' sudden force vto 'the car, such as may occur in yswitching and'in making up trains and the like, so that an excessive amount of slack is taken up.4

, The principal object of my invention is' j Yto provide means for preventing4 theacci,v

view of another vention.

dental operation .of the slackadjuster under the above conditions. Y

. In 'the'accompanying drawing;,Fig. y1 is a vertical central section of-'al car-truckvwith my improved/slack,adjuster appliedvthere-V to; Fig. 2 an enlarged detail view of a por# tionof the take-up` mechanism; Fig.y 3 an elevational view illustrating aV modifiedl form of `my invention; and-Fig-4v asimilar modiiied form of my rin-v- In Fig. .14 of the drawingsis shown the usual car lbrake mechanism comprising brake shoes 1 'carried by brake beams 2, a live brake lever 3, operatively connected to the brake cylinder (not shown), and a dead lever 4, pivotally connected to the live `lever by, a rigid rod 5, the brake beams being pivotally connected to the levers 8 and 4 by lugs 6 and 7 respectively,

The slack adjuster comprises Aa ratchet bar 8, pivotally supported by a bracket 9, secured to the bolster 10, and pivoted to the dead lever 4f is a pawl 11 adapted toengage the teeth of the rachet bar 8, the under side of the bar 8 being adapted to rest on a roller 12 secured to the lever 4f.. A sleeve ,15 is mounted on an adjusting rod 16, having its opposite end pivotally secured to the pivot pin 17 of the live lever'3. Secured to the sleeve 15 is a detent 18 adapted to engage teeth 19 cut on the rod 16 and carried the sleeve :a: lug 24, an elongated slot 13 through which the pivot pink 14' extends,Vv

For manually-y adjustingl v:the 'i sleeve. 515;," la; j

and'projectsunderthe detent-l8, so that by `rocking,member 2O is mounted onfthe sleeve l" "60j operating the linger piece 21, the detent18 may be raised" out of engagement with'fthe teeth-1.9:.. A'eles Spring@ oonnootooi to' a fixed ROlOHO the truck is attached', to a projecting `portion 'of the lveljelve3- for;v described is' oo follows; when the brakes are applied4 by yoperation, o'fthejbrake' f vcylinder 'inthe usual waythe live'lever I3' is moved against the resistance of thez'fspring 2 2,4 The'` lowerv ends ,ofgthe leversv=j3 andy l being maintained at "a constantfdis'tance apart-,by `the rod 5," thebrakebeams 2 are"` 1 separated, causing the brake shoes 111 tofbe' applied to the car vvheels23.`

Thefpivot pins 14 and y17. "are thus sepavl rated, vand in the normal operationofj the4 brake, the amount of Y separation is just due ,towear of thevbr'ake shoes, the movement exceeds the vnormaliamount,'fthe*pinY 14 will engage the endfofftlie slot13 and f g the'.live lever 3 assumes its normal position` uponfrelease of the brakes, `ft'he 'detent 18 will prevent return'move'mentofthesleeve,y

and the pin litinally engagingthefoppo# site end of the slo'tjlvvillcause a movement of the dead lever andfthe'pfawl `llover` one orinoreof the teethon'the.ratchet bar 8, to complete the operation of taking up slack.`

`According to my invention, in order to prevent accidental movement of the dead.`

lever l and the pawl 11 from taking up slack lthrough momentum action lol'- the parts,

as shown in Fig. 1, a 'toot-hed bar 25 may -be pivotally mounted at one endv on the ratchet bar 8, the. other end of the barrhavi'ng an elongated` slot1 26 in which projects a pin 27,

secured to the ratchet bar 8. A pawl 28 is secured yto, theouter end ofthe dead lever 4:v l d d and When the bar 25 is moved upwardly on its pivot, the .pavvl is adapted to engage the l`when the carfis subjected to sudden shocks, j

teeth of the bar 25. Below the bar 25, a

weighted 'ratchet arm 29v is pivotally mountfl man ed on the bar 8 and engages the under side of said bar.

In operation, when the car is subjected to a severe shock, in the direction tending to shift the lever 4 and the paWl 1l along the teeth on the ratchet bar 8, the Weighted arm 29 Will swing on its pivot through its momentum, and act on the bar 25, so as to litt the same and cause engagement of the pawl 28 with the teeth on the bar. Slack adjusting movement of the lever 4 and the paWl l1 is thus prevented and the parts remain in their normal positions ofl adjustment.

In Fig. 3, a slightly modified form of my invention is shown, in which a Weighted arm 29, pvotally mounted on the lever 4, is provided with a paivl or detent 30 adapted'to engage teeth 3l, cut or cast in the side face of the bar 8. Upon a sudden change in velocity of the car, in aA direction tending to cause the paWl ll to move along'the teeth of the bar and take up slack, the inertia of the arm 29 will eil'ect the swinging movement of the arm, so that the. detent 3() Will engage one of the `teeth 31 and thus prevent the take-up movementv of the lever 4 and the paWl 11.

Another form of the invention is shown in Fig. 4, in Which an additionalpawl or detent 33, having aweighted arm 32 associated therewith, is adapted to engage teeth 34 cut in the bar 8., a coil return spring 35 tending to hold the paWl 38 out of engagement with the teeth 34 on the bar 8". IVhen the car is subjected' to a shock, the inertia of the Weight 32 causes movement of the detent so that the detent Will engage the teeth 34 of the bar 8 and thus prevent movement oi the lever 4 and the paWl ll to take up slack.

Having now described my invention, what I claim as new and desire to secure by Iletters Patent, is :e

l. The combination with a brake slack adjuster, of means operated by momentum 'for preventing accidental operation of the slack adjuster to take up slack.'

2. The combination With a brake slack adupon an abrupt changein juster, of' means operative upon a sudden change in velocity of the car for preventing the operation of the slack adjuster' to take up slack.

3. T he combination with a brake sla-ck adjuster, or" means operative by ymomentum velocity of the car for locking the slack adjuster against operation to take up slack.

4. In a brake slack adjuster, the combination With a ratchet bar and a paivl engaging the teeth of the ratchet bar to take up slack, of an additional paWl and ratchet operated by momentum to prevent the opera-tion of the slack adjuster to take up slack.

5. In a brake slack adjuster, the combination with a ratchet bar and a pawl4 engaging the teeth ot' the ratchet bar to take up slack,

of additional ratchetV teeth associated withA said bar, a detent for engaging said teeth'yto oppose movement of the paWl onthe ratchet bar, and means operated by momentum iior causing engagement between the detent and said teeth.

6. In a brake slack adjuster, the combination With a ratchet bar, a brake lever, and a` paivl carried by said lever for engaging,thev ratchet teeth of the bar to take up slack, of

additional ratchet teeth associated With said bar and a Weighted detent operable by mo.- mentum for engaging the additional ratchet teeth to prevent movement of said paWl to take up slack.

7. In a brake slack adjuster, the combination With a ratchet bar, a brake lever, and a paWl carried by said lever for engaging the ratchet teeth of the bar to take up slack, or' additional ratchet teeth associated With said bar and a weighted detent pivotally mounted on the brake lever and movable by momentum to engage the additional ratchet teeth to prevent relative movement of the pavvl to take up slack.

In testimony whereof I have hereuntol set my hand. y CLYDE C. FARMER. 

